From ea62504373fa9ff3ced27e07e1eac041888ecc46 Mon Sep 17 00:00:00 2001 From: Xin Long Date: Fri, 17 Feb 2017 12:45:41 +0800 Subject: [PATCH] sctp: add a function to verify the sctp reconf chunk This patch is to add a function sctp_verify_reconf to do some length check and multi-params check for sctp stream reconf according to rfc6525 section 3.1. Signed-off-by: Xin Long Signed-off-by: David S. Miller --- include/net/sctp/sm.h | 3 ++ net/sctp/sm_make_chunk.c | 59 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 62 insertions(+) diff --git a/include/net/sctp/sm.h b/include/net/sctp/sm.h index f6a828d3d072..ca9fbfb2084c 100644 --- a/include/net/sctp/sm.h +++ b/include/net/sctp/sm.h @@ -277,6 +277,9 @@ struct sctp_chunk *sctp_make_strreset_tsnresp( struct sctp_association *asoc, __u32 result, __u32 sn, __u32 sender_tsn, __u32 receiver_tsn); +bool sctp_verify_reconf(const struct sctp_association *asoc, + struct sctp_chunk *chunk, + struct sctp_paramhdr **errp); void sctp_chunk_assign_tsn(struct sctp_chunk *); void sctp_chunk_assign_ssn(struct sctp_chunk *); diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c index 60d9fdcef440..969a30c7bb54 100644 --- a/net/sctp/sm_make_chunk.c +++ b/net/sctp/sm_make_chunk.c @@ -3801,3 +3801,62 @@ struct sctp_chunk *sctp_make_strreset_tsnresp( return retval; } + +bool sctp_verify_reconf(const struct sctp_association *asoc, + struct sctp_chunk *chunk, + struct sctp_paramhdr **errp) +{ + struct sctp_reconf_chunk *hdr; + union sctp_params param; + __u16 last = 0, cnt = 0; + + hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr; + sctp_walk_params(param, hdr, params) { + __u16 length = ntohs(param.p->length); + + *errp = param.p; + if (cnt++ > 2) + return false; + switch (param.p->type) { + case SCTP_PARAM_RESET_OUT_REQUEST: + if (length < sizeof(struct sctp_strreset_outreq) || + (last && last != SCTP_PARAM_RESET_RESPONSE && + last != SCTP_PARAM_RESET_IN_REQUEST)) + return false; + break; + case SCTP_PARAM_RESET_IN_REQUEST: + if (length < sizeof(struct sctp_strreset_inreq) || + (last && last != SCTP_PARAM_RESET_OUT_REQUEST)) + return false; + break; + case SCTP_PARAM_RESET_RESPONSE: + if ((length != sizeof(struct sctp_strreset_resp) && + length != sizeof(struct sctp_strreset_resptsn)) || + (last && last != SCTP_PARAM_RESET_RESPONSE && + last != SCTP_PARAM_RESET_OUT_REQUEST)) + return false; + break; + case SCTP_PARAM_RESET_TSN_REQUEST: + if (length != + sizeof(struct sctp_strreset_tsnreq) || last) + return false; + break; + case SCTP_PARAM_RESET_ADD_IN_STREAMS: + if (length != sizeof(struct sctp_strreset_addstrm) || + (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS)) + return false; + break; + case SCTP_PARAM_RESET_ADD_OUT_STREAMS: + if (length != sizeof(struct sctp_strreset_addstrm) || + (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS)) + return false; + break; + default: + return false; + } + + last = param.p->type; + } + + return true; +} -- 2.39.2